Steven Pinker: How 'Common Knowledge' Rules Our Lives

The Essence of Common Knowledge

• 💡 Common knowledge is a technical concept in game theory, philosophy, linguistics, and economics, distinct from merely knowing a fact.
• 🎯 It means not only "I know X and you know X," but also "I know that you know X, and you know that I know X, ad infinitum."
• 🧠 This embedded knowledge is crucial for coordination, enabling two or more people to make choices that benefit them both, like driving on the same side of the road or meeting at a specific location.

Generating and Impacting Coordination

• 👁️ Common knowledge is psychologically generated when something is public, conspicuous, or self-evident, such as through direct observation or eye contact.
• 🗣️ In language, blurting something out creates common knowledge, which can challenge social relationships, whereas innuendo allows for plausible deniability.
• 🚨 An example is Joe Biden's debate performance, which transformed private concerns about his age into common knowledge, leading to a coordinated public response.

Common Knowledge in Politics and Power

• 🚫 Dictators actively suppress common knowledge through censorship and banning public assemblies to prevent collective action and maintain control.
• 📜 The "blank leaflets" joke from the Soviet Union and Chinese censorship of coordination attempts (not just complaints) illustrate this suppression.
• 🌍 The Arab Spring demonstrates how a single incident, like the Tunisian fruit peddler's protest, can generate communal outrage and cascading events when it becomes common knowledge, signaling a shared intolerable affront.

Social Dynamics and Relationships

• 🤝 In negotiations, leaks can make concessions common knowledge, signaling weakness and undermining a party's bargaining position.
• 🤫 Dog whistling is a tactic to avoid creating common knowledge across all groups, instead communicating privately to a specific base.
• 😂 Laughter is a powerful, involuntary common knowledge generator that can puncture "spirals of silence" and challenge dominance hierarchies, fostering egalitarianism in friendships.

Tact, Honesty, and Relationships

• 💔 While often seen as positive, radical honesty can destroy relationships because many social bonds are maintained by "fictions" or things kept out of common knowledge.
• 🎭 Tact, diplomacy, and politeness serve a vital purpose in preserving relationships by preventing certain truths from becoming common knowledge, even if privately understood.
• ✅ Understanding this balance helps navigate social interactions, recognizing that some degree of "rational hypocrisy" is essential for maintaining harmony.